1. Field of Use
The present invention relates to an input/output data processing system and, more particularly, to a system for balancing the utilization of input/output (I/O) processing units.
2. Prior Art
An important factor affecting the processing efficiency of a data processing system is input/output activity. This factor becomes even more important in larger systems operating in a multiprogramming environment. In such systems, any imbalance of input/output activity results in an inefficient use of system resources as well as degradation in the overall system processing efficiency.
In order to provide for a reasonable level of efficiency, some systems include operating system routines for estimating what the load is and then assigning system process resources based upon that estimate. However, it has been found that unless the estimate includes the many time dependent factors which change dynamically, such an arrangement is unable to take advantage of dynamic changes in the laod.
In those prior art systems which are able to take certain ones of the time dependent variables into account, the processing overhead required to estimate the load becomes extremely high.
Accordingly, it is a primary object of the present invention to provide a system whose performance is improved by balancing the utilization of process resources.
It is another object of the present invention to provide an input/output processing system in which a load is balanced between a pair of input/output processing units thereby resulting in improved processig efficiency.
It is still a more specific object of the present invention to provide an input/output processing system which takes advantage of dynamic changes in the load to provide for balanced utilization of system processig units while requiring little increase in system complexity and apparatus.